The present invention relates to storage containers and more particularly relates to portable plastic storage containers. In its most immediate sense, the present invention relates to portable plastic storage containers in which an upright frame contains drawers which pivot open and shut.
In a known container of this type, a vertical frame contains pivotable drawers which are linked together to open and close together. (This linkage is provided to make it possible to lock the drawers shut in an inexpensive manner; to lock all the drawers, it is only necessary to lock one.) The drawers are secured to the frame by axially aligned pivot pins which are driven into the drawers and which extend through, and rotate within, open pivot holes in the frame.
This known container has two major disadvantages. The first of these is that the container is relatively expensive. (This is a severe drawback since such products are sold in a highly price-sensitive market.) This expense comes about because the pins themselves are costly and assembly is labor-intensive, since each drawer must be individually secured within the frame using a pair of pins.
The second disadvantage is that the container can easily tip over when heavily loaded. This is because the pins are located relatively close to the front of the frame. As a result, when the loaded drawers are pivoted open, the center of gravity of the loaded container can be shifted forward of the front of the frame and the container can tip over.
It would be advantageous to provide a container of this type which would be less expensive to manufacture and less likely to tip over when loaded.
In accordance with the invention, the drawers are provided with integral axially aligned pivot shafts and the frame has mating recesses in which the pivot shafts are retained. Ramped grooves in the frame connect the recesses with the front of the frame, and the distance between the bottom surfaces of corresponding grooves decreases from a maximum at the front of the frame to a minimum immediately adjacent the recesses.
When the drawers are inserted into the frame, the pivot shafts are guided toward the recesses by the grooves but the drawers are slightly compressed and the frame is slightly expanded as the insertion process continues. Once the pivot shafts reach the recesses, the pivot shafts snap in place and the drawers and frame regain their undistorted shapes. In this way, the drawers are pivotally supported within the frame without the use of metal pins. Additionally, all the drawers can be simultaneously inserted into, and secured within, the frame. Thus, the cost of the metal pins is completely eliminated and the costs of assembly are substantially reduced.
In accordance with the preferred embodiment of the invention, the recesses are more than one third of the distance behind the front surface of the frame; advantageously, the distance between the front surface and the recesses is approximately 40% of the depth of the frame. When the drawers of the preferred embodiment are fully opened, it is quite unlikely that the center of gravity of the loaded container can move forward of the front of the frame. In this way, the container is less likely to tip over when the drawers are opened.